Hollow anatomical structures (HAS) may include, without limitation, veins, arteries, gastric structures, coronary structures, pulmonary structures, and tubular structures associated with reproductive organs. These and other HAS provide various functions throughout the body, but in some instances require intervention to correct a physical defect or ailment.
For example, the venous system contains numerous one-way valves for directing blood flow back to the heart. Venous valves are usually bicuspid valves, with each cusp forming a sack or reservoir for blood. Retrograde blood flow forces the free surfaces of the cusps together to prevent continued retrograde flow of the blood and enables only antegrade blood flow to the heart. When an incompetent valve is in the flow path, the valve is unable to close because the cusps do not form a proper seal and retrograde flow of the blood cannot be stopped. When a venous valve fails, increased strain and pressure occur within the lower venous sections and overlying tissues, sometimes leading to additional failure of other valves distal to the first incompetent valve. Two venous conditions or symptoms that often result from valve failure are varicose veins and more symptomatic chronic venous insufficiency (CVI).
Another condition that can result from valve failure is pelvic congestion syndrome (PCS). It is believed that PCS is associated with varicose veins in the pelvis (lower abdomen and groin). Often, the varicose veins develop during pregnancy and continue to progress in size. The syndrome is associated with constant dull pelvic pain, pressure and heaviness. One method of alleviating the pain and cosmetic issues due to varicose veins, CVI or PCS is to occlude the vein to divert blood flow to other, healthy veins.